It is _________ you speak ill of others behind them __________ she hates you.

Here are three books on history. Which one would you like to borrow一______. You see, I’m interested in geography these days.

When a basketball game is held, there is always an interval ______ players can have a break.

I made ________ a rule to exercise every day.

20. _________raining hard for 3 hourswithout stopping.21.